A known disc brake apparatus for a railway vehicle is configured to use the principle of leverage (e.g., refer to patent document 1). Patent document 1 describes a disc brake apparatus that includes a pair of brake heads, a pair of caliper levers, and an actuator.
The brake heads are located at opposite sides of a wheel and hold pair of brake pads. The brake heads are coupled to the caliper levers. Each caliper lever is pivotal about a fulcrum pin extending in a generally vertical direction. Each caliper lever is connected to the actuator. The actuator drives each caliper lever so that the caliper lever pivots about the fulcrum shaft. This structure rotates the caliper levers. Consequently, the brake pads, which are held by the brake heads on the caliper levers, contact a disc and apply a braking force to the disc.    Patent Document 1: Japanese Laid-Open Patent Publication No. 2006-315422 (“abstract”)